Blue litmus paper turning red means that the solution where the litmus paper was submerged is an acidic solution with a pH of less than 7. Another verification of the nature of the solution is the turning to red of methyl orange in acidic solutions. The answer then is D.
Solution:- Hypochlorite ion 
has one Cl and one O atom. Cl has 7 valence electrons and O has 6 valence electrons. Since there is one negative charge on the ion,
total valence electrons = 7 + 6 +1 = 14
(note:- if there is negative charge then it is added and if there is positive charge then it is subtracted while calculating the valence electrons)
Both Cl and O atoms wants to complete their octet and so for this we put a single bond between them. Single bond means two electrons, so the remaining electrons would be 14 - 2 = 12
It means 12 electrons will be placed as lone pair of electrons. To complete the octet, we put 6 dots around each of the atom. Oxygen is more electron negative than Cl, so we show the -1 charge for oxygen.
The statements that describe a nuclear reaction are may involve a change in total mass, involve very high-energy changes, and involve changes in nuclides when decay takes place.
There are two kinds of nuclear reactions, that is, fission and fusion. Fusion involves the fusion of two light atoms into a heavier atom, while fission involves the splitting of an unstable isotope (with a high mass number) into stable elements of lower mass number, which vary in features from the parent atoms. Both the reactions discharge huge concentration of energies in the process.
